Schroth Rallye Quick Fit 4 point ASM - not compatible with any HANS?? Is this a new thing?

[Woods247]

Even though it has become a moot point given the built in “weak link” in th e QF ASM harness, which is what makes it incompatible with the HANS, I’d like to understand the “too wide” issue with the lap belt. Either side is adjustable, and I am curious as to what the beef is - is it because it has a lap belt clasp rather than a 4/5/6 point harness hub?

Yes. That’s exactly why. My HANS would slide under the ASM. It doesn’t with the Pro.

 

[Woods247]

No actual data points, but I hear this from many car prep people/fabricators, NOT about those QF Pro belts specifically, but just about using ANY type of harness in a car not equipped with at least a semi-cage, if not a full, multi-point certified cage, used at high speeds on a track, even if the 'tail strap' brackets/plates are properly mounted at the less than 45* angle required to prevent spinal compression in an 'incident'.

Now, this could all be bogus, and it might just be that these prep companies and fabricators want everyone to hand them many thousands of bucks for a fully built cage, and shell seats/mounts/back braces/etc. (I am asking this SERIOUSLY, and without ANY snideness, or snark whatsoever.)

Of course, these same prep/fabricators also do not care that the car becomes NOT street legal/usable at that point either.

Look, I am STILL trying to determine, and decide if even using one piece, composite material, shell racing seats in a street driven car with the factory 3 points, without ANY type of back bracing at all, is actually unsafe/deadly in a street accident or not (and I don't mean because of getting rid of the seat air bag either).

Understood. The data provided by Schroth and the accidents I’ve seen guys walk away from while using the ASM and Pro harnesses are good enough for me. I completely understand why others may disagree though. This is one of the most debated topics in our hobby. This and bolt-in cages.

 

[maestromaestro]

Yes. That’s exactly why. My HANS would slide under the ASM. It doesn’t with the Pro.

Hmm... I am confused- are you saying that even though Schroth calls it an ASM harness, IF you had a HANS device on you'd submarine? And all that because it uses a belt clasp/buckle vs. using a 4-6 pt hub? And if you weren't wearing a HANS device - no submarining? How? The way the QF ASM works, as discussed, is by yielding and effecting a body rotation, which is obviously quite different from the 6pt harness' action. I just don't follow... [I hope you didn't find this out firsthand, the hard way... ]

I am really trying to understand how this would happen - as I have a 6pt Schroth in my 911 and the QF ASM one holds me as tight as the 6 pt one, so I can't figure out how one would slide under the belt section, never mind the ASM "feature". Schroth doesn't want us using with the HANS because of the body rotation which would supposedly render the HANS ineffective, not because you'd sumbarine if you had one on... I must be missing something here.

 

[Woods247]

Hmm... I am confused- are you saying that even though Schroth calls it an ASM harness, IF you had a HANS device on you'd submarine? And all that because it uses a belt clasp/buckle vs. using a 4-6 pt hub? And if you weren't wearing a HANS device - no submarining? How? The way the QF ASM works, as discussed, is by yielding and effecting a body rotation, which is obviously quite different from the 6pt harness' action. I just don't follow... [I hope you didn't find this out firsthand, the hard way... ]

I am really trying to understand how this would happen - as I have a 6pt Schroth in my 911 and the QF ASM one holds me as tight as the 6 pt one, so I can't figure out how one would slide under the belt section, never mind the ASM "feature". Schroth doesn't want us using with the HANS because of the body rotation which would supposedly render the HANS ineffective, not because you'd sumbarine if you had one on... I must be missing something here.

Perhaps HMS could answer this better than me.

I took this from their website:
“Schroth's revolutionary Quick Fit Pro is the world's first 4 point harness that is designed to be used with a HANS Device in your stock seats! Now the safety and peace of mind that come from driving with a HANS device is available to the Driver's School and Open track day participant.

The secret behind this revolutionary design is the integration with the vehicle's existing safety system and an innovative geometry maximizing effectiveness of the HANS Device. Conventional 4 point restraints do not join at a center Cam Lock, they are sewn to lap belts leaving them almost 6-8 inches apart from each other. The design of the Quick Fit Pro is such that both shoulder belts angle in towards the Cam Lock facilitating use with a HANS Device.

Like the Standard Quick Fit Harnesses, the Quick Fit Pro clicks into the car's female seat belt receptacles. This alerts the airbag computer to the fact that someone is in the seat and restrained, as well as takes advantage of the seat belt pre-tensioner. This device ignites a pyrotechnic charge in the event of an accident that will tighten the lap belt. This integration into the factory safety system is a very important part of the Schroth Quick Fit Pro.

These harnesses are designed to be used in stock seats that have passed a seat back strength test. Quick Fit harnesses are not approved for any fixed back or aftermarket seats. Now you don't have to spend $3,000 on a Rollbar, seats and 6 point harnesses.”

 

[Woods247]

Notice the difference between the two lap belts. The top is the Pro, which works with HANS, the bottom is the standard QuickFit. Both have ASM technology. I do not know I the extra flap that pulls out during impact will jeopardize the effectiveness of a HANS. I will call and ask tomorrow.

 

[maestromaestro]

Perhaps HMS could answer this better than me.

I took this from their website:
“Schroth's revolutionary Quick Fit Pro is the world's first 4 point harness that is designed to be used with a HANS Device in your stock seats! Now the safety and peace of mind that come from driving with a HANS device is available to the Driver's School and Open track day participant.

The secret behind this revolutionary design is the integration with the vehicle's existing safety system and an innovative geometry maximizing effectiveness of the HANS Device. Conventional 4 point restraints do not join at a center Cam Lock, they are sewn to lap belts leaving them almost 6-8 inches apart from each other. The design of the Quick Fit Pro is such that both shoulder belts angle in towards the Cam Lock facilitating use with a HANS Device.

Like the Standard Quick Fit Harnesses, the Quick Fit Pro clicks into the car's female seat belt receptacles. This alerts the airbag computer to the fact that someone is in the seat and restrained, as well as takes advantage of the seat belt pre-tensioner. This device ignites a pyrotechnic charge in the event of an accident that will tighten the lap belt. This integration into the factory safety system is a very important part of the Schroth Quick Fit Pro.

These harnesses are designed to be used in stock seats that have passed a seat back strength test. Quick Fit harnesses are not approved for any fixed back or aftermarket seats. Now you don't have to spend $3,000 on a Rollbar, seats and 6 point harnesses.”

Thanks for staying engaged, I mean it.

So, it is a bit clearer...

I find it ironic that HSM/Schroth appear at a first glance to disavow using the QF ASM as it has the clasp buckle rather than a cam; I suppose that's why the use the word "conventional". I still don't quite get their logic - they imply that there is no need for more than 4 pts in any harness. In the QF ASM, it's the body rotation that prevents from sliding under (so, no HANS); in the PRO, it is the "unique geometry" that keeps the shoulder belts "angled down" (so, HANS is OK), but what stops you from submarining - the cam?? If so, and the trick is to have a cam, why do they then sell the 6 pt harnesses?

I fully understand that we (I) have migrated off topic - I do by now have the answer as to why no HANS with QF ASM. But, now, the new question is how does the PRO prevent sliding underneath if it still has 4 pts...

 

[M-Sport fan]

Perhaps HMS could answer this better than me.

I took this from their website:
“Schroth's revolutionary Quick Fit Pro is the world's first 4 point harness that is designed to be used with a HANS Device in your stock seats! Now the safety and peace of mind that come from driving with a HANS device is available to the Driver's School and Open track day participant.

The secret behind this revolutionary design is the integration with the vehicle's existing safety system and an innovative geometry maximizing effectiveness of the HANS Device. Conventional 4 point restraints do not join at a center Cam Lock, they are sewn to lap belts leaving them almost 6-8 inches apart from each other. The design of the Quick Fit Pro is such that both shoulder belts angle in towards the Cam Lock facilitating use with a HANS Device.

Like the Standard Quick Fit Harnesses, the Quick Fit Pro clicks into the car's female seat belt receptacles. This alerts the airbag computer to the fact that someone is in the seat and restrained, as well as takes advantage of the seat belt pre-tensioner. This device ignites a pyrotechnic charge in the event of an accident that will tighten the lap belt. This integration into the factory safety system is a very important part of the Schroth Quick Fit Pro.

These harnesses are designed to be used in stock seats that have passed a seat back strength test. Quick Fit harnesses are not approved for any fixed back or aftermarket seats. Now you don't have to spend $3,000 on a Rollbar, seats and 6 point harnesses.”

According to this, there is NO added 'danger' to using these (with the factory seats), even without a HANS, and even on the street?
(As long as one follows the less than 45* angle tail strap mounting rule?)

Their supposedly street legal, FIA approved, Profi 2 ASM FE systems also use that same DOT/NHTSA legal button release center lock as well.

It IS a bit confusing though, since they claim in their text that a lot of these harness systems are "meant to be used as a 4 point", but then offer the options on almost all of them (save for the non-center lock, 'conventional/OEM type' center buckled, Rallye, and QF ASMs) for either a split to single attachment point '5 point' sub belt, or a fully individually mounted 6 point sub belt.

 

[maestromaestro]

According to this, there is NO added 'danger' to using these (with the factory seats), even without a HANS, and even on the street?
(As long as one follows the less than 45* angle tail strap mounting rule?)

Their supposedly street legal, FIA approved, Profi 2 ASM FE systems also use that same DOT/NHTSA legal button release center lock as well.

It IS a bit confusing though, since they claim in their text that a lot of these harness systems are "meant to be used as a 4 point", but then offer the options on almost all of them (save for the non-center lock, 'conventional/OEM type' center buckled, Rallye, and QF ASMs) for either a split to single attachment point '5 point' sub belt, or a fully individually mounted 6 point sub belt.

Indeed. I suppose this exposes the inherent conflict of interest - they are, after all, in business of selling "stuff". So, they figured that a cheaper Rallye harness would appeal to certain folks, and the ASM "feature" is a major selling point. However, I don't think that they have enough evidence/data to convince the racing/tracking crowd that the 6 pt harnesses are unnecessary "anymore" - so, they can sell those as well. Having the cake and eating it too. Thus, the confusing "explanations", as they want to talk out both ends of their mouth. It would be helpful if we could see specifics on the limits of each type (I would imagine the impact energy is a big factor in this).

 

[Woods247]

Thanks for staying engaged, I mean it.

So, it is a bit clearer...

I find it ironic that HSM/Schroth appear at a first glance to disavow using the QF ASM as it has the clasp buckle rather than a cam; I suppose that's why the use the word "conventional". I still don't quite get their logic - they imply that there is no need for more than 4 pts in any harness. In the QF ASM, it's the body rotation that prevents from sliding under (so, no HANS); in the PRO, it is the "unique geometry" that keeps the shoulder belts "angled down" (so, HANS is OK), but what stops you from submarining - the cam?? If so, and the trick is to have a cam, why do they then sell the 6 pt harnesses?

I fully understand that we (I) have migrated off topic - I do by now have the answer as to why no HANS with QF ASM. But, now, the new question is how does the PRO prevent sliding underneath if it still has 4 pts...

I think the key is in how the belt is adjusted when you sit in the car. The instructions mention many times that the lap belt must sit across the upper part of your thighs and be tightened securely prior to adjusting the shoulder harnesses. For me, this took some practice and seat adjusting before I was comfortable. Cinching down the lapbelt FIRST is key to keeping us from sliding under it. I make it extremely tight for this reason.

FWIW, I have a lower back injury from decades of MTB and Enduro moto racing, so I’m very sensitive to compression. I’m 6’ tall and don’t feel as if the QF Pro compresses me in the seat. If it did, there’s no way I could use it ha! I’m curious about the the extra patch/HANS compatibility though. I’m definitely going to follow up on that.

 

[maestromaestro]

I think the key is in how the belt is adjusted when you sit in the car. The instructions mention many times that the lap belt must sit across the upper part of your thighs and be tightened securely prior to adjusting the shoulder harnesses. For me, this took some practice and seat adjusting before I was comfortable. Cinching down the lapbelt FIRST is key to keeping us from sliding under it. I make it extremely tight for this reason.

FWIW, I have a lower back injury from decades of MTB and Enduro moto racing, so I’m very sensitive to compression. I’m 6’ tall and don’t feel as if the QF Pro compresses me in the seat. If it did, there’s no way I could use it ha! I’m curious about the the extra patch/HANS compatibility though. I’m definitely going to follow up on that.

I'd be very interested in what they tell you regarding this "extra flap". There is some voodoo there, it seems. I am expecting their vacillating and prevaricating, as they want to sell both kinds of harnesses. Color me skeptical.

[There is also the whole business of harnesses not being "legal" for the street; I can't really understand that either.]

 

[M-Sport fan]

The instructions mention many times that the lap belt must sit across the upper part of your thighs and be tightened securely prior to adjusting the shoulder harnesses. For me, this took some practice and seat adjusting before I was comfortable. Cinching down the lapbelt FIRST is key to keeping us from sliding under it. I make it extremely tight for this reason.

This is the method I used when I had a set of their old, original, Rallye 3 street harnesses in my old '89 GTI 16V for autocross.

I even got a set of those adjuster rods shown in some of the pics on their site, which insert into those end loops on the belts, so that one can get more leverage/grip on the belt to adjust/tighten them down.

I wonder if they would have considered my setup 'unsafe' though, since I had an old, no longer made now, Sparco 'shell style' recliner (both the seat back and seat bottom parts were made of fiberglass composite) in that car.